How to make Potassium Nitrate by The Jolly Roger
Potassium Nitrate is an ingredient in making fuses, among other things. Here is how you make it: 

Materials needed: 

3.5 gallons of nitrate bearing earth or other material 
1/2 cup of wood ashes 
Bucket or other similar container about 4-5 gallons in volume 
2 pieces of finely woven cloth, each a bit bigger than the bottom of the bucket 
Shallow dish or pan at least as large in diameter as the bucket 
Shallow, heat resistant container 
2 gallons of water 
Something to punch holes in the bottom of the bucket 
1 gallon of any type of alcohol